U.S. patent number 10,634,942 [Application Number 15/926,526] was granted by the patent office on 2020-04-28 for electro-optical device and electronic device having base member, lens member and first and second insulators.
This patent grant is currently assigned to SEIKO EPSON CORPORATION. The grantee listed for this patent is SEIKO EPSON CORPORATION. Invention is credited to Satoshi Ito, Daisuke Sawaki.
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United States Patent |
10,634,942 |
Ito , et al. |
April 28, 2020 |
Electro-optical device and electronic device having base member,
lens member and first and second insulators
Abstract
An electro-optical device includes a pixel electrode, a light
shielding, a first insulator, a second insulator provided to be in
contact with the first insulator on an opening region, a base
member including a concave portion disposed to an outside of the
second insulator and overlapped with the second insulator, and a
lens member provided on the base member to cover the concave
portion, and having the refractive index higher than that of the
base member, in which the second insulator functions as a waveguide
which reflects incident light at an interface between the second
insulator and the first insulator, and propagates the incident
light inside the second insulator, and the lens member refracts the
incident light incident on the lens member from the second
insulator or the incident light incident on the second insulator
from the lens member at an interface with the concave portion.
Inventors: |
Ito; Satoshi (Eniwa,
JP), Sawaki; Daisuke (Shiojiri, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
SEIKO EPSON CORPORATION |
Tokyo |
N/A |
JP |
|
|
Assignee: |
SEIKO EPSON CORPORATION (Tokyo,
JP)
|
Family
ID: |
63917101 |
Appl.
No.: |
15/926,526 |
Filed: |
March 20, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180314087 A1 |
Nov 1, 2018 |
|
Foreign Application Priority Data
|
|
|
|
|
Apr 26, 2017 [JP] |
|
|
2017-086944 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F
1/133526 (20130101); G02F 1/136209 (20130101); G02F
1/133524 (20130101); G02F 1/133345 (20130101); G02F
1/133512 (20130101) |
Current International
Class: |
G02F
1/1333 (20060101); G02F 1/1362 (20060101); G02F
1/1335 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
2002-091339 |
|
Mar 2002 |
|
JP |
|
2005-333042 |
|
Dec 2005 |
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JP |
|
2006-184877 |
|
Jul 2006 |
|
JP |
|
2013-073181 |
|
Apr 2013 |
|
JP |
|
2017-072630 |
|
Apr 2017 |
|
JP |
|
Primary Examiner: Wilson; Paisley L
Attorney, Agent or Firm: Oliff PLC
Claims
What is claimed is:
1. An electro-optical device comprising: a pair of substrates; and
a liquid crystal layer that is interposed between the pair of
substrates; one of the pair of substrates including: a pixel
electrode; a light shielding member that includes a first light
shielding layer, a second light shielding layer that is disposed
between the pixel electrode and the first light shielding layer,
and a third light shielding layer that is disposed between the
pixel electrode and the second light shielding layer; a first
insulator that is overlapped with the light shielding member in a
planar view, the first insulator including a first insulating layer
covering the first light shielding layer, a second insulating layer
covering the second light shielding layer, and a third insulating
layer covering the third light shielding layer, the first
insulating layer having a first side surface in a region surrounded
by the light shielding member, the second insulating layer having a
second side surface in the region surrounded by the light shielding
member, the third insulating layer having a third side surface in
the region surrounded by the light shielding member; a second
insulator that is provided to be in contact with the first side
surface of the first insulating layer, the second side surface of
the second insulating layer, and the third side surface of the
third insulating layer in the region surrounded by the light
shielding member, the second insulator having a refractive index
higher than that of the first insulating layer, the second
insulating layer, and the third insulating layer; a base member
that includes a concave portion; and a lens member that is provided
on the base member, the lens member having a refractive index
higher than that of the base member, wherein an edge of the lens
member is disposed outside the second insulator in the planar
view.
2. The electro-optical device according to claim 1, wherein the
second insulator is disposed by being separated from the light
shielding member.
3. The electro-optical device according to claim 1, wherein the
second insulator and the lens member are separated from each other
in a thickness direction.
4. The electro-optical device according to claim 1, wherein the
first insulator is disposed between the lens member and the second
insulator in a thickness direction.
5. The electro-optical device according to claim 1, wherein the
second insulator is disposed to a position close to the lens member
with respect to the light shielding member in a thickness
direction.
6. An electronic device comprising the electro-optical device
according to claim 1.
7. The electro-optical device according to claim 1, wherein the
second insulator is in contact with the lens member.
Description
BACKGROUND
1. Technical Field
The present invention relates to an electro-optical device and an
electronic device.
2. Related Art
A liquid crystal display device including a liquid crystal layer
between an element substrate provided with a plurality of pixel
electrodes and switching elements and a counter substrate disposed
opposite to the element substrate is known. In correspondence with
each pixel electrode, an opening region which is a region
transmitting light is provided. In the liquid crystal display
device, it is required to improve light utilization efficiency by
suppressing incident light from deviating from the opening
region.
In JP-A-2013-73181, a technology in which a lens (microlens) is
provided in the opening region of the element substrate is
disclosed. In JP-A-2013-73181, a concave portion including a bottom
having a shape corresponding to the lens is formed in the opening
region by dry etching using a light shielding layer defining the
opening region as a mask. Then, by filling the concave portion with
glass or resin, a lens is formed.
However, in the technology described in JP-A-2013-73181, a
disposition region of a lens is limited to the inside of an opening
region.
SUMMARY
An advantage of some aspects of the invention is to provide a novel
technology capable of improving light utilization efficiency by
using a lens which can be disposed to the outside of an opening
region in an electro-optical device such as a liquid crystal
display device and an electronic device including the
electro-optical device.
According to an aspect of the invention, there is provided an
electro-optical device including: a pixel electrode; a light
shielding member that is provided along an edge of the pixel
electrode in a planar view viewed in a thickness direction that is
a direction perpendicular to the pixel electrode; a first insulator
that is provided in a region overlapped with at least the light
shielding member, and formed of a first material of light
transmission in the planar view; a second insulator that is
provided to be in contact with the first insulator on an opening
region surrounded by the light shielding member in the planar view,
and formed of a second material, having a refractive index higher
than that of the first material, of the light transmission; a base
member that includes a concave portion disposed to an outside of
the second insulator which is overlapped with the second insulator
and is formed of a third material of the light transmission in the
planar view; and a lens member that is provided on the base member
to cover the concave portion, and formed of a fourth material,
having the refractive index higher than that of the third material,
of the light transmission, in which the second insulator functions
as a waveguide which reflects incident light incident on the second
insulator at an interface between the second insulator and the
first insulator, and propagates the incident light inside the
second insulator, and the lens member is disposed between the
second insulator and the base member in the thickness direction,
and refracts the incident light incident on the base member by
being transmitted from a second insulator side to the lens member
or the incident light incident on the second insulator by being
transmitted from a base member side to the lens member at an
interface with the concave portion.
According to the configuration, by providing the second insulator
as the waveguide, since it is possible to suppress the incident
light from deviating from the opening region, the light utilization
efficiency is improved. Furthermore, since it is possible to
refract the incident light passing through the outside of the
second insulator to the inside of the opening region by the lens
member provided to cover a concave portion disposed to the outside
of the second insulator in the planar view, it is possible to
further improve the light utilization efficiency.
In the electro-optical device, the second insulator and the lens
member may be separated from each other in the thickness direction.
According to the configuration, since it is not necessary to form
the second insulator to the thickness reaching the lens member, it
is possible to easily form the second insulator.
In the electro-optical device, the second insulator may be disposed
to a position close to the lens member with respect to the light
shielding member in the thickness direction. According to the
configuration, even if the second insulator and the lens member are
separated from each other, light emitted from the second insulator
can be easily incident on the lens member, or the light emitted
from the lens member can be easily incident on the second
insulator.
In the electro-optical device, the second insulator and the lens
member may be in contact with each other in the thickness
direction. According to the configuration, it is possible for light
to be directly incident on the lens member from the second
insulator, or it is possible for light to be directly incident on
the second insulator from the lens member.
In the electro-optical device, the lens member may include a lens
layer that is disposed in a range in which the concave portion is
provided in the thickness direction, and a light transmission layer
that is disposed in a second insulator side with respect to the
lens layer in the thickness direction. According to the
configuration, by adjusting the thickness of the light transmission
layer, it is possible to adjust an optical path length of light
transmitting the opening region.
In the electro-optical device, the electro-optical device further
includes a semiconductor element that is provided in a position in
which a first light shielding layer and a second light shielding
layer are overlapped with each other in the planar view, and
provided between the first light shielding layer and the second
light shielding layer in the thickness direction, in which the
light shielding member includes the first light shielding layer and
the second light shielding layer disposed in a position different
from that of the first light shielding layer in the thickness
direction, and a portion that is overlapped with the first light
shielding layer in the planar view, and a range in which the second
insulator is disposed in the thickness direction includes a range
from a surface facing a semiconductor element side of the first
light shielding layer to a surface facing a semiconductor element
side of the second light shielding layer in the thickness
direction. According to the configuration, it is possible to
suppress irradiation of the incident light to the semiconductor
element.
In the electro-optical device, the second insulator may be disposed
by being separated from an inside of the opening region with
respect to an edge of the light shielding member and provided in
contact with the first insulator in the planar view. According to
the configuration, it is possible to suppress reflection of the
incident light by the edge of the light shielding member.
According to another aspect of the invention, there is provided an
electronic device of the invention including the electro-optical
device.
In the electro-optical device, by the second insulator and the lens
member included in the electro-optical device, the light
utilization efficiency in the electronic device is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying
drawings, wherein like numbers reference like elements.
FIG. 1 is a schematic planar view showing a configuration of a
liquid crystal display device according to an embodiment.
FIG. 2 is an equivalent circuit diagram showing an electrical
configuration of the liquid crystal display device according to the
embodiment.
FIG. 3 is a schematic sectional view showing a configuration of the
liquid crystal display device according to the embodiment.
FIG. 4 is a schematic planar view showing a configuration in the
vicinity of a pixel electrode.
FIG. 5 is a schematic planar view showing a disposition in an edge
of a concave portion included in a base member of an element
substrate.
FIG. 6 is a schematic planar view showing another disposition in
the edge of the concave portion included in the base member of the
element substrate.
FIG. 7 is a schematic sectional view showing a manufacturing
process of the liquid crystal display device according to the
embodiment.
FIG. 8 is a schematic sectional view showing another manufacturing
process of the liquid crystal display device according to the
embodiment.
FIG. 9 is a schematic sectional view showing still another
manufacturing process of the liquid crystal display device
according to the embodiment.
FIG. 10 is a schematic sectional view showing still another
manufacturing process of the liquid crystal display device
according to the embodiment.
FIG. 11 is a schematic sectional view showing still another
manufacturing process of the liquid crystal display device
according to the embodiment.
FIG. 12 is a schematic sectional view showing still another
manufacturing process of the liquid crystal display device
according to the embodiment.
FIG. 13 is a schematic sectional view showing still another
manufacturing process of the liquid crystal display device
according to the embodiment.
FIG. 14 is a schematic sectional view showing a configuration of a
liquid crystal display device according to a second embodiment.
FIG. 15 is a schematic sectional view showing a configuration of a
liquid crystal display device according to a third embodiment.
FIG. 16 is a schematic sectional view showing a configuration of a
liquid crystal display device according to a fourth embodiment.
FIG. 17 is a schematic diagram showing an optical system of a
projector according to an application example.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Hereinafter, preferred embodiments of the invention will be
described in detail with reference to the accompanying drawings and
the like. However, in each figure, the dimensions and scales of
each part are appropriately different from the actual ones. In
addition, since the embodiments described below are preferable
specific examples of the invention, various technical limitations
are given, but the scope of the invention is not limited to these
forms unless otherwise stated to limit the invention in the
following description.
First Embodiment
As one embodiment of the invention, an active matrix type liquid
crystal display device 100 including a thin film transistor (TFT)
as a switching element of a pixel is exemplified.
FIG. 1 is a schematic planar view showing an example of an overall
configuration of the liquid crystal display device 100. The liquid
crystal display device 100 includes an element substrate 200, a
counter substrate 300 disposed opposite to the element substrate
200, and a liquid crystal layer 400 disposed between the element
substrate 200 and the counter substrate 300.
The element substrate 200 and the counter substrate 300 are bonded
through a sealing material 410 disposed in a frame shape. The
liquid crystal layer 400 is formed of a liquid crystal having
positive or negative dielectric anisotropy sealed in a space
surrounded by the element substrate 200, the counter substrate 300,
and the sealing material 410.
For example, the sealing material 410 is made of an adhesive such
as a thermosetting or ultraviolet curable epoxy resin. In the
sealing material 410, a spacer for maintaining a constant interval
between the element substrate 200 and the counter substrate 300 is
mixed. A peripheral portion 420 made of a light shielding material
is formed inside a formation region of the sealing material 410.
The inside of the peripheral portion 420 is a display region 101 in
which a plurality of pixels are arranged.
On a region outside the sealing material 410, a data line driving
circuit 110 and an external circuit mounting terminal 120 are
provided along one side of the element substrate 200 and a scanning
line driving circuit 130 is provided along two sides adjacent to
the one side. On the remaining side of the element substrate 200, a
plurality of wirings 140 for connecting between the scanning line
driving circuits 130 on both sides are provided. At the corner
portion of the counter substrate 300, an inter-substrate conducting
material 150 for providing electrical conduction between the
element substrate 200 and the counter substrate 300 is
provided.
For example, the liquid crystal display device 100 is operated in a
twisted nematic (TN) mode or a vertical alignment (VA) mode. For
example, the liquid crystal display device 100 is used as a
transmissive display device that modulates light incident from a
counter substrate 300 side and emits light to an element substrate
200 side.
FIG. 2 is an equivalent circuit diagram showing an example of an
electrical configuration of the liquid crystal display device 100.
A plurality of pixels 102 are arranged in a matrix on the display
region 101. A pixel electrode 270 and a TFT 260 are provided on
each pixel 102. A source electrode of the TFT 260 is electrically
connected to a data line 262 extending from the data line driving
circuit 110 (see FIG. 1). Image signals (data signals) S1, S2, . .
. , Sn are sequentially supplied from the data line driving circuit
110 to the data line 262. A gate electrode of the TFT 260 is
electrically connected to a scanning line 261 extending from the
scanning line driving circuit 130 (see FIG. 1). Scanning signals
G1, G2, . . . , Gn are sequentially supplied from the scanning line
driving circuit 130 to the scanning line 261. A drain electrode of
the TFT 260 is electrically connected to the pixel electrode
270.
The image signal S1, S2, . . . , Sn are written into the pixel
electrode 270 at a predetermined timing through the data line 262
by turning on the TFT 260 for a certain period. The image signal of
a predetermined level written in the liquid crystal layer 400
through the pixel electrode 270 in this manner is held for a
certain period by liquid crystal capacitance formed with a common
electrode 370 (see FIG. 3) provided in the counter substrate
300.
In order to prevent the held image signal S1, S2, . . . , Sn from
leaking, a storage capacitor 290 is formed between the pixel
electrode 270 and a capacitor line 263, and disposed in parallel to
the liquid crystal capacitance. In this manner, a voltage signal is
applied to a liquid crystal of each pixel 102 and an alignment
state of the liquid crystal is changed according to the applied
voltage level such that light incident on the liquid crystal layer
400 (see FIG. 3) is modulated and gradation display becomes
possible.
FIG. 3 is a schematic sectional view showing an example of a
configuration of the liquid crystal display device 100. Viewing the
liquid crystal display device 100 in a direction (direction
perpendicular to surface of pixel electrode 270 facing liquid
crystal layer 400 side) perpendicular to the pixel electrode 270 is
referred to as planar view. A direction perpendicular to the pixel
electrode 270 may be referred to as a thickness direction. Viewing
the liquid crystal display device 100 in a direction perpendicular
to a plane on which a base member 210 of the element substrate 200
is formed or a direction perpendicular to a plane on which a base
member 310 of the counter substrate 300 is formed may be referred
to as planar view.
Hereinafter, for the convenience of description, with respect to
the element substrate 200, the liquid crystal layer 400 side may be
referred to as an upper side and with respect to the counter
substrate 300, and the liquid crystal layer 400 side may be
referred to as an upper side.
The element substrate 200 includes the base member 210, a lens
member (microlens) 220, an insulating layer 231, an insulating
layer 232, an insulating layer 233, an insulating layer 234, an
insulating layer 235, a high refractive index insulator 240, a
light shielding layer 251, a light shielding layer 252, a light
shielding layer 253, a TFT 260, the pixel electrode 270, and an
alignment film 280. On an upper side of the base member 210 (liquid
crystal layer 400 side), the lens member 220, the insulating layer
231, and the like, the high refractive index insulator 240, the
light shielding layer 251, the TFT 260, the pixel electrode 270,
the alignment film 280, and the like are provided.
The base member 210 is formed of a material of light transmission
that transmits visible light, for example, glass, quartz, or the
like. A surface on an upper side (liquid crystal layer 400 side) of
the base member 210 has a concave portion 211 having a concave
curved surface 211a.
The lens member 220 is formed on the base member 210 covering the
concave portion 211. The lens member 220 is formed of the material
of the light transmission, for example, silicon oxynitride, silicon
nitride, or the like. As the material (fourth material) forming the
lens member 220, a material of which a refractive index with
respect to the visible light is higher than the refractive index of
the material (third material) forming the base member 210 is
used.
The lens member 220 includes the lens layer 221 disposed in a range
in the thickness direction in which the concave portion 211 is
provided and a light transmission layer 222 disposed on the upper
side (on high refractive index insulator 240 side) of the lens
layer 221 in the thickness direction. The lens layer 221 is formed
in contact with the concave portion 211 so as to fill the concave
portion 211, forms an interface 223 with the concave portion 211,
and includes a convex curved surface 221a corresponding to the
concave curved surface 211a of the concave portion 211. A shape of
the concave curved surface 211a of the concave portion 211, that
is, a shape of the convex curved surface 221a of the lens layer 221
may be a spherical surface or an aspheric surface. The light
transmission layer 222 is a flat plate portion of an upper side of
the lens layer 221 in the lens member 220.
The insulating layer 231 is formed on the lens member 220. The
insulating layer 231 is formed of a material insulation and light
transmission, for example, silicon oxide or the like. The
insulating layer 232, the insulating layer 233, the insulating
layer 234, and the insulating layer 235 can also be formed by using
the same material as the insulating layer 231.
The light shielding layer 251 is formed on the insulating layer
231. The light shielding layer 251 is formed of a light shielding
material that shields the visible light, for example, polysilicon,
metal, metal silicide, a metal compound, or the like. The light
shielding layer 252 and the light shielding layer 253 can also be
formed by using the same material as the light shielding layer
251.
The insulating layer 232 is formed on the insulating layer 231
covering the light shielding layer 251. The TFT 260 is formed on
the insulating layer 232. The TFT 260 includes a semiconductor
layer, and a source region, a channel region, and a drain region of
the transistor are provided on the semiconductor layer. On the
insulating layer 232 covering the TFT 260, the insulating layer 233
is formed. The light shielding layer 252 is formed on the
insulating layer 233. As the light shielding layer 252, for
example, the scanning line 261 (see FIG. 2) can be used. The
insulating layer 234 is formed on the insulating layer 233 covering
the light shielding layer 252. The light shielding layer 253 is
formed on the insulating layer 234. As the light shielding layer
253, for example, the data line 262 (see FIG. 2) can be used. The
insulating layer 235 is formed on the insulating layer 234 covering
the light shielding layer 253.
The light shielding layer 251 (first light shielding layer) and the
light shielding layer 252 (disposed in position different from
light shielding layer 251 in thickness direction)(second light
shielding layer) are overlapped with each other in the planar view.
The TFT 260 (semiconductor element and switching element) is
provided in a position in which the light shielding layer 251 and
the light shielding layer 252 are overlapped with each other in the
planar view, and provided between the light shielding layer 251 and
the light shielding layer 252 in the thickness direction. The light
shielding layer 253 overlaps with the light shielding layer 251 and
the light shielding layer 252 in the planar view.
The insulating layer 231 is provided in the vicinity of the light
shielding layer 251 in a lower side of the light shielding layer
251, the insulating layer 232 is provided in the vicinity of the
light shielding layer 251 covering the light shielding layer 251,
the insulating layer 233 is provided in the vicinity of the TFT 260
covering the TFT 260, the insulating layer 234 is provided in the
vicinity of the light shielding layer 252 covering the light
shielding layer 252, and the insulating layer 235 is provided in
the vicinity of the light shielding layer 253 covering the light
shielding layer 253.
On a region of the lens member 220 in which the insulating layer
231, the insulating layer 232, the insulating layer 233, the
insulating layer 234, and the insulating layer 235 are not
provided, the high refractive index insulator 240 is formed in a
range of thickness up to a top surface of the insulating layer 235.
The high refractive index insulator 240 is formed of the material
of the insulation and the light transmission, for example, silicon
oxynitride, silicon nitride, or the like. As a material (second
material) forming the high refractive index insulator 240, a
material of which the refractive index with respect to the visible
light is higher than that of a material (first material) forming
the insulating layer 231, the insulating layer 232, the insulating
layer 233, the insulating layer 234, and the insulating layer 235
(low refractive index insulator 230 described later) is used. As a
material forming the high refractive index insulator 240, for
example, a material having the same refractive index as that of a
material forming the lens member 220 can be used.
On a surface on which the insulating layer 235 and the high
refractive index insulator 240 is formed, the pixel electrode 270
is formed. The pixel electrode 270 is formed of a material of
conductivity and light transmission, for example, indium tin oxide
(ITO), indium zinc oxide (IZO), or the like. On the insulating
layer 235 and the high refractive index insulator 240 covering the
pixel electrode 270, the alignment film 280 is formed. The
alignment film 280 is formed of, for example, polyimide, silicon
oxide, or the like.
An insulating layer or having the refractive index lower than that
of the high refractive index insulator 240 which is provided in a
range in the thickness direction in which the high refractive index
insulator 240 (second insulator) is disposed and provided in
contact with the high refractive index insulator 240 in the planar
view, is collectively referred to as a low refractive index
insulator 230 (first insulator). In this example, the insulating
layer including the insulating layer 231, the insulating layer 232,
the insulating layer 233, the insulating layer 234, and the
insulating layer 235 collectively form the low refractive index
insulator 230. In addition, the light shielding layer 251, the
light shielding layer 252, and the light shielding layer 253 are
collectively referred to as a light shielding member 250.
The counter substrate 300 includes the base member 310, the lens
member (microlens) 320, an insulating layer 330, the common
electrode 370, and an alignment film 380. On an upper side of the
base member 310 (on liquid crystal layer 400 side), the lens member
320, the insulating layer 330, the common electrode 370, and the
alignment film 380 are provided.
The base member 310 is formed of the material of the light
transmission, for example, the glass, the quartz, or the like. A
surface of an upper side (liquid crystal layer 400 side) of the
base member 310 includes a concave portion 311 including a concave
curved surface 311a. The lens member 320 is formed on the base
member 310 covering the concave portion 311. The lens member 320 is
formed of the material of the light transmission, for example,
silicon oxynitride, silicon nitride, or the like, having a
refractive index higher than that of a material forming the base
member 310 with respect to the visible light.
The lens member 320 includes a lens layer 321 disposed in a range
in the thickness direction in which the concave portion 311 is
provided and a light transmission layer 322 disposed on an upper
side of the lens layer 321 in the thickness direction. The lens
layer 321 includes a convex curved surface 321a in contact with the
concave portion 311 by being formed to fill the concave portion
311, which forms an interface 323 with the concave portion 311, and
corresponds to the concave curved surface 311a of the concave
portion 311. A shape of the concave curved surface 311a including
the concave portion 311, that is, a shape of the convex curved
surface 321a including the lens layer 321 may be the spherical
surface or the aspheric surface. The light transmission layer 322
is a flat plate portion of an upper side of the lens layer 321 in
the lens member 320.
The insulating layer 330 is formed on the lens member 320. The
insulating layer 330 is formed of the material of the insulation
and the light transmission, for example, silicon oxide or the like.
The common electrode 370 is formed on the insulating layer 330. The
common electrode 370 is formed of the material of the conductivity
and the light transmission, for example, ITO, IZO, of the like. The
alignment film 380 is formed on the common electrode 370. The
alignment film 380 is formed of, for example, polyimide, silicon
oxide, or the like.
FIG. 4 is a schematic planar view showing an example of a
configuration in the vicinity of the pixel electrode 270, and shows
a positional relationship between the low refractive index
insulator 230, the high refractive index insulator 240, the light
shielding member 250, the TFT 260, and the pixel electrode 270 in
the planar view. FIG. 3 is a sectional view obtained by selecting
an appropriate position (path) in the planar view so as to show a
schematic configuration of the base member 210, the lens member
220, the low refractive index insulator 230, the high refractive
index insulator 240, the light shielding member 250, the TFT 260,
and the pixel electrode 270, in a sectional view taken in a
direction perpendicular to the thickness direction.
In FIG. 4, the pixel electrode 270 is indicated by a solid line.
The light shielding layer 251 is indicated by a dotted line, the
light shielding layer 252 formed by the scanning line 261 is
indicated by a broken line, and the light shielding layer 253
formed by the data line 262 is indicated by a dashed line. The high
refractive index insulator 240 is indicated by a hatched region in
which a solid line and a dashed line in left upward are alternately
repeated, and the low refractive index insulator 230 is indicated
by a non-hatched (white) region (open region). The TFT 260 is
indicated by a region hatched by a solid line in left upward.
Here, the direction along one side where the data line driving
circuit 110 (see FIG. 1) is provided is an X direction, and two
sides opposed to each other and perpendicular to the one side, that
is, a direction along two sides in which the scanning line driving
circuit 130 (see FIG. 1) is provided is a Y direction. As a
direction perpendicular to the X direction and the Y direction is a
Z direction, viewing the liquid crystal display device 100 from the
Z direction may be referred to as the planar view.
The pixel electrode 270 is a rectangular shape having a pair of
sides extending in the X direction and another pair of sides
extending in the Y direction. A plurality of the pixel electrodes
270 are arranged in a matrix so that a row extending in the X
direction and a column extending in the Y direction are formed.
The light shielding layer 251 is provided in a mesh shape so as to
cover a gap extending in the X direction between rows of the pixel
electrodes 270 and a gap extending the Y direction between columns
of the pixel electrodes 270 in the Y direction. The light shielding
layer 251 is provided to cover an edge portion of the pixel
electrode 270, and the gap between the pixel electrodes 270
adjacent in the X direction and the gap between the pixel
electrodes 270 adjacent in the Y direction are covered with the
light shielding layer 251 over the entire width.
The light shielding layer 252 (scanning line 261) is provided to
cover the gap extending between the rows of the pixel electrode 270
in the X direction. The light shielding layer 252 is provided to
cover an edge of the pixel electrode 270, and a gap between the
pixel electrodes 270 adjacent in the Y direction is covered with
the light shielding layer 252 over the entire width.
The light shielding layer 253 (data line 262) is provided to cover
the gap extending the Y direction between the rows of the pixel
electrodes 270. The light shielding layer 253 is provided to cover
the edge portion of the pixel electrode 270, and the gap between
the pixel electrodes 270 adjacent in the X direction is covered
with the light shielding layer 253 over the entire width.
Therefore, the light shielding member 250 including the light
shielding layer 251, the light shielding layer 252, and the light
shielding layer 253 are provided in a mesh shape so as to cover the
gap extending between the rows of the pixel electrode 270 in the X
direction, and the gap extending between the rows of the pixel
electrodes 270 in the Y direction. The light shielding member 250
is provided to cover the edge portion of the pixel electrode 270,
the gap between the pixel electrodes 270 adjacent in the X
direction and the gap between the pixel electrodes 270 adjacent in
the Y direction are covered with the light shielding member 250
over the entire width.
The light shielding member 250 is provided along (to overlap with
edge 271) an edge 271 of the pixel electrode 270 in the planar
view, and an opening region 272 (surrounded by edge 255 of light
shielding member 250) surrounded by the light shielding member 250
is a light transmission region through which light is transmitted
without being blocked by the light shielding member 250. The
non-opening region 273 disposed outside the opening region 272 is a
region overlapping with the light shielding member 250 and is a
light shielding region in which the light is shielded.
The TFT 260 is disposed in a position in which the light shielding
layer 252 that is the scanning line 261 and the light shielding
layer 253 that is the data line 262 are overlapped (intersected)
with each other, and provided in a region overlapping with the
light shielding member 250.
The low refractive index insulator 230 is provided in a region
overlapping with at least the light shielding member 250. The high
refractive index insulator 240 is provided in contact with the low
refractive index insulator 230 on the opening region 272.
More preferably, the low refractive index insulator 230 is provided
to extend from the edge 255 of the light shielding member 250 to
the outside (inside opening region 272), and cover an end surface
of the light shielding layer 251 and the light shielding layer 252
(see FIG. 3). Correspondingly, the high refractive index insulator
240 is more preferably disposed so as to be separated from the edge
255 of the light shielding member 250 to the inside of the opening
region 272, and provided so as not to be in contact with the light
shielding member 250. In this manner, the high refractive index
insulator 240 is provided so as to be in contact with the low
refractive index insulator 230 over the entire circumference of the
opening region 272.
Furthermore, with reference to FIG. 3, FIG. 5, and FIG. 6, a
positional relationship between the concave portion 211 of the base
member 210 and the high refractive index insulator 240 will be
described. As described in FIG. 3, a region 242 in which the high
refractive index insulator 240 is disposed is disposed inside the
opening region 272. A region 212 in which the concave portion 211
is disposed is disposed to the outside of the opening region 272 so
as to overlap with the opening region 272 and the concave portion
211 is disposed to the outside of the high refractive index
insulator 240 overlapping with the high refractive index insulator
240 in the planar view.
FIG. 5 and FIG. 6 are schematic planar views showing an example of
disposition of an edge 213 of the concave portion 211. The edge 255
of the light shielding member 250 defining the edge 213 of the
concave portion 211 and the pixel electrode 270, the high
refractive index insulator 240, and the opening region 272 are
shown. The concave portion 211 is provided for each pixel electrode
270, and disposed in a matrix. A shape of the edge 213 of the
concave portion 211 in the planar view is not particularly limited,
and may be, for example, a circular shape, or may be, for example,
a quadrilateral shape. FIG. 5 shows an example of a case where the
edge 213 is the circular shape and FIG. 6 shows an example of a
case where the edge 213 is the quadrilateral shape.
In a portion in which the edge 213 is disposed outside the high
refractive index insulator 240, the concave portion 211 is disposed
outside the high refractive index insulator 240. The entire
periphery of the edge 213 may not be disposed outside the high
refractive index insulator 240. That is, at least a part of the
circumference of the concave portion 211 in the planar view may be
disposed outside the high refractive index insulator 240. The
concave portion 211 includes a portion disposed outside the high
refractive index insulator 240, and a portion disposed outside the
opening region 272 (edge 255).
With reference to FIG. 3 and FIG. 4, a function of the high
refractive index insulator 240 as a waveguide and a function of the
lens member 220 will be described. In the liquid crystal display
device 100, a traveling direction is aligned in a direction
appropriately perpendicular to the pixel electrode 270 such that
light appropriately converted into parallel light flux is incident,
but the incident light also includes a component that is obliquely
incident while being shifted from a direction perpendicular to the
pixel electrode 270.
Here, as an example of a case where light is incident on the liquid
crystal display device 100 from the counter substrate 300 side, a
function as the waveguide of the high refractive index insulator
240 for incident light 500 obliquely incident on the opening region
272 will be described. The incident light perpendicularly incident
on the opening region 272 travels straight in the opening region
272.
The incident light 500 obliquely incident on the opening region 272
transmits the alignment film 280 and the pixel electrode 270, is
incident on the high refractive index insulator 240, and is
incident on the interface 241 between the high refractive index
insulator 240 and the low refractive index insulator 230. The
interface 241 is provided to be perpendicular to the pixel
electrode 270. It is not essential for an actual device to be
vertical (90.degree.) without error, and an angle formed by the
interface 241 with respect to the pixel electrode 270 (with respect
to plane parallel to pixel electrode 270) may be an angle close to
vertical, for example, an angle within a range of
90.degree..+-.10.degree.. Since the angle of the interface 241 is
an angle close to vertical, total reflection described below is
likely to occur at the interface 241.
For example, in a case where the low refractive index insulator 230
is formed of silicon oxide and the high refractive index insulator
240 is formed of the silicon oxynitride, for visible light of
wavelength 550 nm, the refractive index of the low refractive index
insulator 230 is 1.46 and the refractive index of the high
refractive index insulator 240 is 1.64. In this example, according
to Snell's law, when the incident angle of the incident light 500
incident on the interface 241 is 62.degree. or more, that is, when
the incident angle to the pixel electrode 270 is 28.degree.
(=90.degree.-62.degree.) or less, the incident light 500 is totally
reflected at the interface 241 and not incident on the low
refractive index insulator 230. Therefore, the incident light 500
is not incident on the non-opening region 273 that is a region in
which the light shielding member 250 is provided in the planar
view.
As described above, the high refractive index insulator 240
functions as the waveguide which reflects light incident on the
opening region 272 (on high refractive index insulator 240) at the
interface 241 between the high refractive index insulator 240 and
the low refractive index insulator 230, and propagates the light
inside the high refractive index insulator 240. By causing total
reflection at the interface 241, it is possible to efficiently
propagate the incident light 500 inside the high refractive index
insulator 240. Even in a case where reflection other than total
reflection occurs at the interface 241, it is possible to return at
least a part of the incident light 500 to the inside of the high
refractive index insulator 240, that is, to the inside of the
opening region 272 by the reflection.
The lens member 220 is disposed between the high refractive index
insulator 240 and the base member 210 in the thickness direction.
The high refractive index insulator 240 and the lens member 220 of
this example are disposed in contact with each other in the
thickness direction.
The incident light 500 incident on the lens member 220 by
transmitting the high refractive index insulator 240 transmits the
lens member 220 and is incident on the base member 210. The
incident light 500 is refracted at the interface 223 between the
lens member 220 and the concave portion 211 of the base member 210,
and can be traveled toward the inside of the opening region 272,
that is, to approach in a direction perpendicular with respect to
the pixel electrode 270, as compared to a case where it is not
refracted at the interface 223.
Since the concave portion 211 is disposed to the outside of the
high refractive index insulator 240 and the lens member 220 (lens
layer 221) is formed by being extended to the outside of the high
refractive index insulator 240, it is possible to travel the
incident light 500 passing through a wide range toward the inside
of the opening region 272, as compared to a case where the lens
member 220 (lens layer 221) is not formed to the outside of the
high refractive index insulator 240.
As described above, in the liquid crystal display device 100, by
providing the high refractive index insulator 240, since it is
possible to suppress the incident light 500 from being deviated
from the opening region 272 as compared to a case where the high
refractive index insulator 240 is not provided, it is suppressed
that the incident light 500 does not contribute to display and
light utilization efficiency is improved. In addition, since it is
possible to suppress irradiation of the incident light 500 on the
TFT 260 (particularly, on semiconductor layer TFT 260) provided in
a position overlapped with the light shielding member 250 in the
planar view, an erroneous operation of the TFT 260 is suppressed.
In this manner, it is possible to improve the light utilization
efficiency and the like with a simple structure in which the high
refractive index insulator 240 is provided on the opening region
272.
Furthermore, by the lens member 220 provided to cover the concave
portion 211 disposed to the outside of the high refractive index
insulator 240 in the planar view, since the incident light 500
passing through the outside of the high refractive index insulator
240 can also be refracted (returned to inside of opening region
272) to the inside of the opening region 272, it is possible to
further improve the light utilization efficiency. For example, in a
projector 700 of an application example (which will be described
below), it becomes easy to cause light to be incident on a
projection optical system 714.
Even in a case where light is incident on the liquid crystal
display device 100 from the element substrate 200 side, similar to
a case where light is incident from the counter substrate 300 side,
the light can be prevented from being incident on the low
refractive index insulator 230 by the high refractive index
insulator 240. With this, the light utilization efficiency is
improved and the irradiation of the incident light 500 to the TFT
260 is suppressed. By the high refractive index insulator 240, an
effect of suppressing the TFT 260 from being irradiated with light
that is reflected by a polarizing plate and again incident on the
element substrate 200 is also obtained.
In addition, for a case where light is incident on the liquid
crystal display device 100 from the element substrate 200 side,
light incident on the lens member 220 from a base member 210 side
is refracted to the inside of the opening region 272 at the
interface 223. With this, since light that is incident on the light
shielding member 250 (non-opening region 273) is suppressed, it is
possible to cause light to be incident on the high refractive index
insulator 240 and it is possible to further improve the light
utilization efficiency.
In this example, the high refractive index insulator 240 and the
lens member 220 are in contact with each other in the thickness
direction. As the high refractive index insulator 240 reaches the
lens member 220, it is possible to directly cause light incident on
the lens member 220 from the high refractive index insulator 240,
or it is possible to directly cause the light incident on the high
refractive index insulator 240 from the lens member 220.
The lens member 220 includes the light transmission layer 222 in
addition to the lens layer 221. By adjusting a thickness of the
light transmission layer 222 of the lens member 220, it is possible
to adjust an optical path length of light transmitting the opening
region 272.
A range in which the high refractive index insulator 240 is
disposed in the thickness direction, it is preferable that the
range include a range in the TFT 260 (particularly, semiconductor
layer of TFT 260) is disposed in the thickness direction. More
specifically, it is preferable that the range include a range from
a surface 251a facing a TFT 260 side of the light shielding layer
251 to a surface 252a facing a TFT 260 side of the light shielding
layer 252 in the thickness direction. By providing the high
refractive index insulator 240 in this manner, it is possible to
suppress the irradiation of the incident light to the TFT 260.
It is preferable that a range in which the high refractive index
insulator 240 is disposed in the thickness direction include a
range from the surface 251a facing the TFT 260 side of the light
shielding layer 251 to the surface 252a facing the TFT 260 side of
the light shielding layer 252 in the thickness direction, even in a
portion in which the high refractive index insulator 240 is
provided in the planar view. With this, it is possible to further
enhance the effect of suppressing the irradiation of the incident
light to the TFT 260.
It is more preferable that a range in which the high refractive
index insulator 240 is disposed in the thickness direction include
a range from a surface 251b opposite to the surface 251a facing the
TFT 260 side of the light shielding layer 251 to a surface 252b
opposite to the surface 252a facing the TFT 260 side of the light
shielding layer 252 in the thickness direction. With this, it is
possible to further enhance the effect of suppressing the
irradiation of the incident light to the TFT 260.
It is more preferable that the high refractive index insulator 240
be disposed to be separated from the edge 255 of the light
shielding member 250 inside the opening region 272 and provided in
contact with the low refractive index insulator 230 in the planar
view. This is due to the following reason.
Since the high refractive index insulator 240 is separated from the
light shielding member 250, the light shielding member 250 is not
in contact with the high refractive index insulator 240 and not
exposed in the high refractive index insulator 240. The light
shielding member 250 is made of metal, for example, and includes
metallic luster. When the light shielding member 250 is exposed
inside the high refractive index insulator 240, light propagating
through the high refractive index insulator 240 is reflected by an
edge of an end portion of the light shielding layer 251 or the like
forming the light shielding member 250.
As the traveling direction of the incident light 500 incident on
the interface 241 is closer to parallel with the interface 241 (as
incident angle to interface 241 is close to 90.degree.), the total
reflection at the interface 241 is likely to occur. However, since
the light reflected at an edge of an end portion of the light
shielding member 250 is not constant in a reflection direction,
there is a possibility that reflected light having a small incident
angle to the interface 241 (reflected light of which traveling
direction is close to perpendicular to interface 241) occurs. Such
reflected light is incident on the low refractive index insulator
230 and propagated by being deviated the opening region 272, and is
more likely to be irradiated on the TFT 260.
By configuring the high refractive index insulator 240 to be
separated from the light shielding member 250, it is possible to
suppress reflection of the incident light 500 by an edge the light
shielding member 250. Even in a configuration where the high
refractive index insulator 240 is in contact with the light
shielding member 250, by providing the high refractive index
insulator 240, as compared to a case where the high refractive
index insulator 240 is not provided, it is possible to obtain the
effect of improving the light utilization efficiency and
suppressing the light irradiation on the TFT 260 as described
above.
Next, a manufacturing method of the liquid crystal display device
100 will be described. FIG. 7 to FIG. 13 are schematic sectional
views showing a manufacturing process of the liquid crystal display
device 100. FIG. 7 is referred. The base member 210 is prepared. In
the base member 210, a mask having an opening on a region in which
the lens member 220 is formed is formed, and a part of a thickness
of the base member 210 in the region is removed by etching. For
this etching, for example, wet etching using an etching solution
containing hydrofluoric acid is used. Thereafter, the mask is
removed.
FIG. 8 is referred. A mask 600 having an opening over the deepest
portion of the concave portion 211 to be formed on the base member
210 is formed. FIG. 9 is referred. For example, by performing the
wet etching using the etching solution containing the hydrofluoric
acid, the concave portion 211 is formed. After the concave portion
211 is formed, the mask 600 is removed.
FIG. 10 is referred. In order to fill the concave portion 211, for
example, silicon oxynitride is deposited by plasma chemical vapor
deposition (CVD), unnecessary portions are removed by chemical
mechanical polishing (CMP), and the upper surface is planarized. In
this manner, the lens member 220 is formed.
FIG. 11 is referred. The insulating layer 231 is formed on the lens
member 220. The light shielding layer 251 is formed on the
insulating layer 231, and the insulating layer 232 is formed on the
insulating layer 231 covering the light shielding layer 251. The
TFT 260 is formed on the insulating layer 232, and the insulating
layer 233 is formed on the insulating layer 232 covering the TFT
260. The light shielding layer 252 is formed on the insulating
layer 233 and the insulating layer 234 is formed on the insulating
layer 233 covering the light shielding layer 252. The light
shielding layer 253 is formed on the insulating layer 234 and the
insulating layer 235 is formed on the insulating layer 234 covering
the light shielding layer 253. As a formation method of the
insulating layer 231, the insulating layer 232, the insulating
layer 233, the insulating layer 234, the insulating layer 235, the
light shielding layer 251, the light shielding layer 252, the light
shielding layer 253, and the TFT 260, known methods can be
appropriately used.
FIG. 12 is referred. On the insulating layer 235, a mask 610 having
an opening on a formation region of the high refractive index
insulator 240 is formed. The insulating layer 235, the insulating
layer 234, the insulating layer 233, the insulating layer 232, and
the insulating layer 231 are formed of, for example, silicon oxide.
The insulating layer 235, the insulating layer 234, the insulating
layer 233, the insulating layer 232, and the insulating layer 231
in an opening of the mask 610 are removed by dry etching using a
halogen-based etching gas such as fluorine such that a concave
portion 611 is formed in the insulating layer 235, the insulating
layer 234, the insulating layer 233, the insulating layer 232, and
the insulating layer 231. After the concave portion 611 is formed,
the mask 610 is removed.
FIG. 13 is referred. In order to fill the concave portion 611, for
example, silicon oxynitride is deposited by plasma CVD, and
unnecessary portions are removed by CMP such that the upper surface
is planarized. In this manner, the high refractive index insulator
240 buried in the concave portion 611 is formed. The high
refractive index insulator 240 according to the present embodiment
can be easily manufactured by burying the concave portion 611.
Thereafter, a structure on the upper side (liquid crystal layer 400
side) than the insulating layer 235 and the high refractive index
insulator 240 is formed by appropriately using a known method such
that the element substrate 200 is formed. Furthermore, the counter
substrate 300 is formed by appropriately using a known technology
and the liquid crystal layer 400 is formed such that the liquid
crystal display device 100 is manufactured.
Another Embodiment
The invention is not limited to the above-described embodiments,
but can be applied to other embodiments as described below, for
example, and various modifications are possible. In addition, in
the other embodiments and modifications described below, one or a
plurality of arbitrarily selected ones can be appropriately
combined.
Second Embodiment
A range in which the high refractive index insulator 240 in which
the waveguide is formed is provided in the thickness direction may
be changed as necessary. In the first embodiment, an example of a
configuration in which the high refractive index insulator 240 is
provided between a surface of a lower side (side opposite to liquid
crystal layer 400) of the insulating layer 231 and a surface of an
upper side (liquid crystal layer 400 side) of the insulating layer
235, that is, a configuration in which the high refractive index
insulator 240 is in contact with the lens member 220 and the pixel
electrode 270, is described.
FIG. 14 is a schematic sectional view showing an example of a
configuration the liquid crystal display device 100 according to
the second embodiment. In the second embodiment, a configuration in
which the high refractive index insulator 240 is provided between a
surface of a lower side of the insulating layer 231 and a surface
of an upper side of the insulating layer 234, that is, a
configuration in which the high refractive index insulator 240 is
in contact with the lens member 220, and not in contact with the
pixel electrode 270, is provided.
Third Embodiment
FIG. 15 is a schematic sectional view showing an example of a
configuration of the liquid crystal display device 100 according to
the third embodiment. In the third embodiment, a configuration in
which the high refractive index insulator 240 is provided between a
position in the thickness direction of the insulating layer 231 and
a surface of an upper side of the insulating layer 234, that is, a
configuration in which the high refractive index insulator 240 is
not in contact with the lens member 220 and the pixel electrode
270, is provided.
Fourth Embodiment
FIG. 16 is a schematic sectional view showing an example of a
configuration of the liquid crystal display device 100 according to
a fourth embodiment. In the fourth embodiment, the configuration in
which the high refractive index insulator 240 is provided between
the position in the thickness direction of the insulating layer 231
and the surface of the upper side of the insulating layer 235, that
is, a configuration in which the high refractive index insulator
240 is not in contact with the lens member 220, and in contact with
the pixel electrode 270, is provided.
Even in the second embodiment to the fourth embodiment, it is
possible to obtain the same effect as the first embodiment,
respectively. That is, by the high refractive index insulator 240,
the light utilization efficiency is improved and the light
irradiation on the TFT 260 is suppressed. In addition, the light
utilization efficiency is further improved by the lens member
220.
A range in which the high refractive index insulator 240 is
provided in the thickness direction can be adjusted by changing a
formation range of the concave portion 611 in which the high
refractive index insulator 240 described in FIG. 12, is provided.
In the second embodiment, by forming the mask 610 on the insulating
layer 234 and by etching to an upper surface of the lens member
220, the concave portion 611 is provided. In the third embodiment,
by forming the mask 610 on the insulating layer 234 and by etching
the mask 610 to a position of the insulating layer 231 in the
thickness direction, the concave portion 611 is provided. In the
fourth embodiment, by forming the mask 610 on the insulating layer
235 and by etching to a position of the insulating layer 231 in the
thickness direction, the concave portion 611 is provided. The
etching to the position of the insulating layer 231 in the
thickness direction is performed by controlling, for example, an
etching time, or, for example, by providing an etching stopper
layer formed of the material of the light transmission at the
position of the insulating layer 231 in the thickness
direction.
In the first embodiment, a configuration in which the high
refractive index insulator 240 is provided in a range of the total
thickness between the lens member 220 and the pixel electrode 270.
On the other hand, in the second embodiment to fourth embodiment,
the high refractive index insulator 240 is provided in a range of a
part of the thickness between the lens member 220 and the pixel
electrode 270. Therefore, the concave portion 611 in which the high
refractive index insulator 240 is provided becomes shallower as
compared to first embodiment and a process of forming the concave
portion 611 becomes easier. In addition, a process for filling a
material forming the high refractive index insulator 240 in the
concave portion 611 becomes easier.
In the second embodiment, similar to the first embodiment, the high
refractive index insulator 240 and the lens member 220 are in
contact with each other in the thickness direction. Therefore,
similar to the first embodiment, it is possible to cause light to
be directly incident on the lens member 220 from the high
refractive index insulator 240, or to cause the light to be
directly incident on the high refractive index insulator 240 from
the lens member 220.
In the third embodiment, the high refractive index insulator 240
and the lens member 220 are separated from each other in the
thickness direction. Therefore, it is not necessary to form the
high refractive index insulator 240 up to a thickness (depth)
reaching the lens member 220, and it is easy to form the high
refractive index insulator 240 as compared to the second
embodiment, and it is easy to form the high refractive index
insulator 240, as compared to the second embodiment. The fourth
embodiment as compared to the first embodiment also has similar
features.
In the third embodiment, the high refractive index insulator 240
and the pixel electrode 270 are separated from each other in the
thickness direction. Therefore, it is not necessary to form the
high refractive index insulator 240 up to a thickness (depth)
reaching the pixel electrode 270, and it is easy to form the high
refractive index insulator 240 as compared to the fourth
embodiment, and it is easy to form the high refractive index
insulator 240, as compared to the fourth embodiment. The second
embodiment as compared to the first embodiment also has similar
features.
As the third embodiment and the fourth embodiment, in a
configuration in which the high refractive index insulator 240 and
the lens member 220 are separated from each other, it is preferable
that the high refractive index insulator 240 be not excessively
separated from the lens member 220 in the thickness direction, and
it is preferable that the high refractive index insulator 240 be
disposed to a position close to the lens member 220 with respect
to, for example, the light shielding member 250 (with respect to
position disposed closest to lens member 220 side of light
shielding member 250).
With this, even if the high refractive index insulator 240 and the
lens member 220 (provided with respect to opening region 272 in
which high refractive index insulator 240 is disposed) are
separated, it is easy to cause light emitted from the high
refractive index insulator 240 is incident on the lens member 220,
and the light emitted from the lens member 220 is incident on the
high refractive index insulator 240. That is, the light emitted
from the high refractive index insulator 240 is suppressed from
being deviated from the lens member 220 and the light emitted from
the lens member 220 is suppressed from being deviated from the high
refractive index insulator 240.
In the liquid crystal display device 100 according to the
above-described embodiment, the following modifications may be
further performed. For example, the number of insulating layers
(interlayer insulating film) and the number of the light shielding
layers forming the light shielding member 250 in the element
substrate 200 may be changed as necessary. In addition, for
example, a range in which the high refractive index insulator 240
is provided in the thickness direction is not limited to those
exemplified in the first embodiment to the fourth embodiment and
may be changed as necessary. In addition, for example, a range in
the planar view in which the high refractive index insulator 240 is
provided in the opening region 272 may be changed as necessary.
Application Example
Next, as an application example of the above-described embodiment,
a projection type display device (projector) will be described.
FIG. 17 is a schematic diagram showing an example of an optical
system of the projector 700 according to the application example.
The projector 700 is configured by including a light source device
701, an integrator 704, a polarization conversion element 705, a
color separation light guide optical system 702, a liquid crystal
light modulation device 710R as a light modulation device, a liquid
crystal light modulation device 710G, a liquid crystal light
modulation device 710B, a cross dichroic prism 712, and the
projection optical system 714. The liquid crystal display devices
720R, 720G, and 720B described below are provided in the liquid
crystal light modulation devices 710R, 710G, and 710B. As the
liquid crystal display devices 720R, 720G, and 720B, for example,
it is possible to use the above-described liquid crystal display
device 100.
The light source device 701 supplies light including red light
(hereinafter, referred to as "R light") that is a first color
light, green light (hereinafter, referred to as "G light") that is
a second color light, and blue light (hereinafter, referred to as
"B light") that is a third color light. As the light source device
701, for example, an extra-high pressure mercury lamp can be
used.
The integrator 704 equalizes illuminance distribution of light
emitted from the light source device 701. Light of which the
illuminance distribution is equalized is converted into polarized
light having a specific oscillation direction, for example,
s-polarized s-polarized light with respect to, a reflecting surface
of the color separation light guide optical system 702 by the
polarization conversion element 705. The light converted into the
s-polarized light is incident on an R light transmitting dichroic
mirror 706R configuring the color separation light guide optical
system 702.
The color separation light guide optical system 702 is configured
by including the R light transmitting dichroic mirror 706R, a B
light transmitting dichroic mirror 706G, three reflecting mirrors
707, and two relay lenses 708.
The R light transmitting dichroic mirror 706R transmits the R
light, and reflects the G light and the B light. The R light
transmitted through the R light transmitting dichroic mirror 706R
is incident on the reflecting mirror 707.
The reflecting mirror 707 bends the optical path of the R light by
90 degrees. The R light bent by the optical path is incident on a
liquid crystal light modulation device 710R for the R light. The
liquid crystal light modulation device 710R for the R light is a
transmissive liquid crystal device which modulates the R light
according to the image signal.
The liquid crystal light modulation device 710R for the R light
includes a .lamda./2 phase difference plate 723R, a glass plate
724R, a first polarizing plate 721R, a liquid crystal display
device 720R, and a second polarizing plate 722R. The .lamda./2
phase difference plate 723R and the first polarizing plate 721R are
arranged in a state of being in contact with a light transmitting
glass plate 724R which does not change a polarization direction. In
FIG. 10, the second polarizing plate 722R is independently
provided, but the second polarizing plate 722R may be arranged in a
state of being in contact with an exit surface of the liquid
crystal display device 720R or an incident surface of the cross
dichroic prism 712.
The G light and the B light reflected by the R light transmitting
dichroic mirror 706R can be bent by 90 degrees in the optical path.
The G light and the B light of which the optical path is bent are
incident on the B light transmitting dichroic mirror 706G. The B
light transmitting dichroic mirror 706G reflects the G light and
transmits the B light. The G light reflected by the B light
transmitting dichroic mirror 706G is incident on the liquid crystal
light modulation device 710G for the G light. The liquid crystal
light modulation device 710G for the G light is the transmissive
liquid crystal device which modulates the G light according to the
image signal. The liquid crystal light modulation device 710G for
the G light includes a liquid crystal display device 720G, a first
polarizing plate 721G, and a second polarizing plate 722G.
The G light incident on the liquid crystal light modulation device
710G for the G light is converted into the s-polarized light. The
s-polarized light incident on the liquid crystal light modulation
device 710G for the G light transmits the first polarizing plate
721G as it is, and is incident on the liquid crystal display device
720G. The s-polarized light incident on the liquid crystal display
device 720G is modulated according to the image signal such that
the G light is converted into p-polarized light. By the modulation
of the liquid crystal display device 720G, the G light converted
into the p-polarized light is emitted from the second polarizing
plate 722G. In this manner, the G light modulated by the liquid
crystal light modulation device 710G for the G light is incident on
the cross dichroic prism 712.
The B light transmitted through the B light transmitting dichroic
mirror 706G is incident on the liquid crystal light modulation
device 710B for the B light through two relay lenses 708 and two
reflecting mirrors 707.
The liquid crystal light modulation device 710B for the B light is
the transmissive liquid crystal device which modulates the B light
according to the image signal. The liquid crystal light modulation
device 710B for the B light includes a .lamda./2 phase difference
plate 723B, a glass plate 724B, a first polarizing plate 721B, a
liquid crystal display device 720B, and a second polarizing plate
722B.
The B light incident on the liquid crystal light modulation device
710B for the B light is converted into the s-polarized light. The
s-polarized light incident on the liquid crystal light modulation
device 710B for the B light is converted into the p-polarized light
by the .lamda./2 phase difference plate 723B. The B light converted
into the p-polarized light transmits the glass plate 724B and the
first polarizing plate 721B as it is and is incident on the liquid
crystal display device 720B. The p-polarized light incident on the
liquid crystal display device 720B is modulated according to the
image signal such that the B light is converted into the
s-polarized light. By the modulation of the liquid crystal display
device 720B, the B light converted into the s-polarized light is
emitted from the second polarizing plate 722B. The B light
modulated by the liquid crystal light modulation device 710B for
the B light is incident on the cross dichroic prism 712.
In this manner, the R light transmitting dichroic mirror 706R and
the B light transmitting dichroic mirror 706G configuring the color
separation light guide optical system 702 separates light supplied
from the light source device 701 into the R light that is the first
color light, the G light that is the second color light, and the B
light that is the third color light.
The cross dichroic prism 712 that is a color combining optical
system is configured by disposing two dichroic films 712a and 712b
orthogonally in an X shape. The dichroic film 712a reflects the B
light and transmits the G light. The dichroic film 712b reflects
the R light and transmits the G light. In this manner, the cross
dichroic prism 712 combines the R light, the G light, and the B
light modulated by the liquid crystal light modulation device 710R
for the R light, the liquid crystal light modulation device 710G
for the G light, and the liquid crystal light modulation device
710B for the B light, respectively.
The projection optical system 714 projects light combined by the
cross dichroic prism 712 on the screen 716. With this, it is
possible to obtain a full color image on the screen 716. As
described above, the above-described liquid crystal display device
100 can be used for the projector 700 as an example.
The above-described liquid crystal display device 100 can be used
for a front projection type projector which projects an image from
a side of observing a projection image or can be used for a rear
projection type projector which projects the image from a side
opposite to the side for observing the projection image.
An electronic device to which the liquid crystal display device 100
can be applied is not limited to the projector. The liquid crystal
display device 100 may be used as a display unit of an information
terminal device such as a projection type HUD (head up display), a
direct view type HMD (head mounted display), an electronic book, a
personal computer, a digital still camera, a liquid crystal
television, a view finder type or monitor direct view type video
recorder, a car navigation system, an electronic notebook, and a
POS.
In the above description, as an example of an electro-optical
device (or display device) including the element substrate 200
(substrate for electro-optical device) having the high refractive
index insulator 240 and the lens member 220 functioning as the
waveguide, the liquid crystal display device 100 is described.
However, the embodiment of the invention is not limited to such a
configuration. The high refractive index insulator 240 and the lens
member 220 functioning as the waveguide may be applied to another
electro-optical device (or display device) such as an
electrophoretic display device and an organic electroluminescence
device in order to, for example, improve the light utilization
efficiency.
The entire disclosure of Japanese Patent Application No.
2017-086944, filed Apr. 26, 2017 is expressly incorporated by
reference herein.
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